D'Addario's Helicore cello D strings are justifiably popular; they offer a warm, rich sound that's remarkably similar to gut or synthetic core strings. Unlike gut, however, their all-metal construction renders them impervious to fluctuations in humidity and temperature. Helicore strings have a multi-strand high-carbon steel core that produces flexible response and range. The core is overlaid with exotic alloy windings that provide extremely quick bow response and outstanding projection. The end result is a versatile string with very long playing life that is extremely stable under all playing conditions.

FEATURES

Ball end string with yellow and blue silking1/8-¾ size available in medium tension; 4/4 size available in light, medium or heavy tensionStranded steel core provides optimum playability and produces a clear, warm toneTitanium windingVersatile string that works well for a wide variety of playing styles and instrumentsAll D'Addario strings are designed, engineered and manufactured in the USA to the most stringent quality controls in the industry

The string is good, works fine. The knob on the tail-pin end was a little bigger than existing, but it fit ok. I wish the specs would give string width (in thousanths of an inch or mm). I wasn't confident I was getting the right thing, and that would be easy to add to the spec.